HEFEI -- Four vehicles caught fire on Wednesday following a pile-up of more than 30 vehicles on an expressway in east China's Anhui Province, according to local fire authorities.

As of 11 a.m., about three hours after the accident occurred in Fuyang City, firefighters rescued 17 people trapped in vehicles, while precise casualties remain unknown.

The blaze was extinguished at 10:38 a.m.. Rescue work is underway.